Mold



Oct.ll,1938. 1 L 2,133,019 I MOLD Filed March 26, 1956 lllli l I 2 ilk mu mum / Eli A INVENTOR.

Y STA/v15) TC4MP54L ATTORNEYS OFFICE f.,:: 1 Stanley T. "Campbell; Cleveland} Ohio, assignor to The Aetna Rubber Company Cleveland. Ohio, at corporation of Ohio Application ren 2c, 1936, i SerialflVo. 70.579

Other objects and advantages of the invention will be apparent from the following description;

of the preferred embodiment thereofde scribed with reference to the. accompanying drawing forming a part of this specification, in which: Fig. l is a longitudinal section, with portions in elevation, through a moldembodying the prese V ent invention;

Fig. 2 is a section on the line 2-2 of Fig. 1; .Fig. 3 is a fragmentary bottom view of the upper half of the mold shown in Figs. 1 and 2;

and

Fig. 4 is a fragmentary plan of the lower half of the mold shown in Figs; 1 and 2. V

The invention is particularly applicable to the molding of cell covers for storage batteries having an internally threaded vent or filler opening therein, and in the preferred embodiment of the invention herein illustrated and described, it is disclosed as embodied in such a mold. It is to be understood, however, that the invention is applicable to the making of other articles and that the preferred embodiment thereof herein shown and described is merely illustrative thereof.

Referring to the drawing the reference character A designates the complete mold which comprises upper and lower half-molds or parts Ill and H, commonly referred to as the block plate and cavity plate, respectively. As previously stated the invention is illustrated as embodied in a mold for forming cell covers; The cell cover made by the particular mold in question is shown in the mold cavity, and is designated in the drawing by the reference character 13. The thread [3 in the vent or filler opening by means of which the vent or. filler plug is secured in the opening in a well known manner extends not more than 360 about the inner wall which defines the vent or filler opening and is adapted to be formed or molded by two members l5 and I 6 carried by the block and cavity plates, respectively, the parting line of which coincides with the meridian line or thelcrest of the thread.

I The ends or faces of the members l5 and I6,

internal threads or the like ens-42 I v which members in effect are projections inthe mold cavity, are inclined,"' and beveled 'around the outside except immediately adjacent that portionlB of the parting line which extends between the ends of the thread. The construction is 5 suchthat when the mold is closed the members l5 and I6 form a cylindrical surface having a spiral groove or thread intermediate the ends thereof. The form of the thread is that of a milled thread, inother words, itappears to have 10 been made by a mill cutter, which may very well be the case.

For the purpose of facilitating manufacture the members l5 and I6 are preferably formed separately, as illustrated, and are fixed in suitable apertures formed in the block and, cavity plates, but it will be apparent that they may be formed integral with the respective parts to which they are attached, in which case they will merely constitute projections thereon. 20

Preferably the thread I3 extendsslightly less than 360 and the portion I8 of the parting line or surface l9 between the two members I5 and I6, which extends between the opposite ends of the thread, is at a slight angle to the direction of relative movement between the plates, that is, to the vertical, as shown, see Fig. 1, to provide draft. The portion l8 of the parting surface is also at a slight angle to the axis of the vent or filler opening. 30

In the particular cell cover illustrated bushing members ll), through which the terminal posts project in use, are molded in the cover at opposite sides of the vent or filler opening. For this purpose the block plate is provided with suitable apertures within which the lower reduced ends of the bushings project and through the medium of whichthey are held in position. Members 2| positioned in the apertures in the block plate assist in holding the bushings in position and may be used as ejectors for removing the finished cover.

From the foregoing description of the preferred embodiment of the invention, it will be apparent that a novel two-part mold has been 45 provided, capable of. producing articles having internal threads. While the preferred embodiited to the particular construction shown which may be varied within the scope of this invention,

' and I particularly point out and claim as my invention the following:

I claim:

l. A mold for forming an article having an 55 internal thread of a single turn, said mold comprising two separable mold members having a said projectionsbeing along the bottom of said groove and e'ztending between the offset ends thereor".

2. A mold for forming a storage cover having a with an internal thread, said mold comprising two separable half-molds ating-a cavity andhaving aligned projections therein the abutting faces of which are spirally arranged and beveled to form a cylindrical core ori'surface having-a spiral groove extending less than 3 61) there:

about, the parting line of said projections being along the bot-tom of,-saidjgrQQve;and

conn cte pp it ends'thereoi. V c i e e 3. A mold for forming an article having an internal thread, said mold comprising two separable mold sections having a cavity with aligned abutting projections therein constituting a cylindrical core, said core being provided on its surface at the parting line between the projections with a'gspiral thread-forming groove of not more than 360 in extent.

4'.A mold for forming an article havingan internal thread, said mold comprising two sept arable mold members having a ca ity and probattery cellvent or filler opening; provided vided therein with alignedjprojections forming a cylindrical core, the ends of the projections abutting each other when the mold is closed and ther abu'tt-ing faces hi the projections being spirallyff ormed and beveled to form on the cylindrical surface of the core a spiral groove of not .I-mGZ'eHthan BGOF, the parting line of said projeetions being along the bottom of said groove and'connecting the opposite ends thereof.

s'rANL' Y 'r. CAMPBELL, 

